Body Fat Percentage | most accurate way to measure, what the # means, and how to change it.

Updated: Jul 16

Not many people know their actual body fat percentage (BF%). There are many machines (bioelectrical impedance based measure), gadgets, and equations that can give you a number, but I am here to tell you, the accuracy level for these are very low! Currently, the most accurate way to measure one's BF%/body composition is with a method called underwater weighing; scientifically known as, hydrostatic weighing. With this method, the subject is submerged into a water tank, seated in a scale (that is connected to a computer system) that looks similar to a harness. The subject is then lowered underwater and asked to expel all air out of their lungs, all while remaining as still as possible. The given numbers are then used to calculate the subjects BF% - separating the measurements of fat mass and lean body mass. Because muscle sinks and fat floats, a person with more body fat will weigh less underwater and be more buoyant. Someone with more muscle mass/lean body weight, however, will weigh more underwater. Interesting, right?! Although underwater weighing is the most accurate way to measure BF%, the lack of availability to this testing makes is less than ideal to use. An accurate method (ranking in at number 4), that fitness professionals typically have access too and knowledge to perform, is the use of a skin fold caliper. With this method, a specific number of sites (5-7) on the subject's body is measured and put into an equation. The subjects body weight, age, gender and 5-7 sites of measure are then put into an equation to determine an accurate measure for their given BF%. The results given from the equation include: lean body mass (pounds), fat mass (pounds), and BF%. So what do all of those numbers even mean? Fat mass is the number of pounds of the subject's current body weight that is fat - a.k.a fat weight. Lean mass is the number of pounds of the subject's current body weight that is muscle - a.k.a lean body weight/lean body weight. And lastly, BF% is the actual percentage of the subject's body that is fat, based on the subject's weight and 5-7 site measures. The below table shows ideal measures of BF%, based on gender and age.

Curious to as what your BF% is? I would love to determine that for you, please reach out so we can arrange a time to meet and do so! Say you are aware of your accurate measure of BF%, lean mass, and fat mass. What do you need to do to improve it? Adopt a healthy lifestyle is the overall answer! Exercise and healthy eating can improve your numbers. Beings everyone is different, the best of both will vary depending on your current weight, fitness level, BF%, lean mass, fat mass, etc. Not sure how to balance all the above to get YOU there? I can help you with that as well and would truly love to be a part of your journey!


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Kindra Waack